FLIES. 



605 



DIPTERA BRACHYCERA (FLIES). 



The flies of this section are generally stouter than those of the last, and 

 may be distinguished from them by their very short antennae, which generally 

 consist only of three joints (never more than six), and often terminate in a 

 long bristle ; the palpi, too, consist of one or two joints only. 



The Stratiomyidce are a family of small or moderate-sized flies of sluggish 

 habits, which are often to be met with on flowers. Some 

 are rather pretty black or black and yellow flies, often with Family 



spines on the scutellum. Many of their larvse live in water Stratiomyidce. 

 or mud. 



The Tabanidce, or gad-flies, are large flies with stout bodies and a very 

 strong proboscis. They vary in length from an inch downwards, and 



are frequently very 

 troublesome in the Family 



woods and fields, by Tabanidce. 

 sucking the blood of Gad-Flies, 

 men and animals. 

 Some are of a plain brown colour, 

 but others are rather pretty, being 

 clothed with golden hair, while others 

 are banded or marked with reddish- 

 yellow. The larvse are harmless, 

 living in damp situations, among 

 fallen leaves, etc.; and, as usual, it is 

 only the female flies which suck blood. 

 We have been speaking here chiefly 



of the genus Tabanus (Linn.), the largest British species of which, T. bomnus 

 (Linn.), is here figured ; but there are several other equally troublesome genera 

 of this family, such as Chrysops, with its variegated wings and beautiful large 

 golden-green eyes ; and Hwmatopoda (Meigen), which 

 contains dull-coloured species, with longer and slenderer 

 bodies than Tabanus and its allies. The species of Hce- 

 matopota are particularly troublesome in the neighbour- 

 hood of woods, especially in rainy weather, one of the 

 Linnean species being actually named plumalis (rainy). 



The next family of interest is that of the Asilidaz, 

 which are large flies, often measuring an inch or more in 

 length, which feed, in the perfect state, 

 on other insects. They have long and Family 



narrow wings, and long bodies, but tHeir comparatively short AxilidcE. 

 and thick legs render it impossible for the most careless Kobber-Flies. 

 observer to mistake them for Tipulidce. A handsome black 

 and yellow species, Asilus crabroniformis (Linn.), is not rare. So far as is 

 known, the larvse feed on vegetable substances, either under the surface of 

 the ground, or in the wood of trees ; but the transformations of most of 

 the species of this family still remain to be discovered. Most flies 

 which are either carnivorous or blood-suckers in their perfect state are 

 vegetable-feeders in their early stages ; but some of the exotic family 

 Midaidce, the perfect insects of which are carnivorous, also feed on insects 

 in the larva state, while the larvse of others live in rotten wood. In the 



Fig. 98. GAD-FLY (Tabanus bovinus). 

 .Nat. size. 



Fig. 99. Hcematopota 

 pluvialis. Nat. size. 



